Pupils at Corstorphine School in Edinburgh have been drinking water throughout the primary school day - and have seen test results improving to the extent that they have already exceeded targets set for 2002.
The theory under consideration is that the human brain uses water in its transmission of neural messages - and that if children are regularly hydrated their brains are better physically equipped to learn.
The school's assistant head, Carol Wood, says that pupils bring bottles of water to school and can drink from them whenever they wish - and that the increased intake of water is now part of the classroom scene.
Dehydrated
Apart from any benefit to children's brains, Ms Wood also says that regular consumption of water has more general health benefits - and that it prevents children from becoming dehydrated throughout the day.
And she also speculates that the process of stopping in order to drink water can help pupils to re-focus their thoughts.
But she was reluctant to see the school's success linked solely to the water experiment - saying that improvements in test results reflected the effectiveness of the teaching and other measures being tried at the Edinburgh primary school.
As well as testing the impact of drinking more water, the innovative school is experimenting with theories based on pupils having different learning styles - such as some preferring to learn visually rather than verbally or through writing.